Cloning of fragments of lambda phage DNA, containing red and gam genes

On the base of plasmid pCV20 (Apr, Tcr mol. weight 5.2 x 10(6) a recombinant plasmid pEH60 (Apr, mol. weight 17.0 x 10(6) with BamHI fragment of phage DNA, containing red+ and gam+ genes was constructed. Selection was found on the ability of phage red- and gam- to propagate in strain E. coli K12 recA-, which was transformed by recombinant plasmid with active red and gam genes. Influence of recombinant plasmid pEH60 on processes of repair and recombination of phage lambda DNA and bacterial DNA was studied. It was shown that red gene in plasmid pEH60 compensates deficiency of redA gene in these processes with phage lambda DNA; in the case of E. coli K12 AB2480 uvr- recA- (pEH60) the processes of multiple reactivation and decombination of phage red- were presented. In the case of bacterial cells, plasmid pEH60 did not compensate deficiency of recA function of bacteria, although it partly compensates deficiency of recBC function. Increase of survival after introduction of plasmid pEH60 in the cell was obtained only for recBC- strain, but not for wild type and recA- strains.